New 3D keyboard

I find the bounce fairly realistic when playing forte and staccato at the same time, but of course when you let off slowly and play more quietly, piano keys don't really bounce.

Yes, and that's the typical technique you want to use as a pianist — after striking a loud note/chord, while holding it you immediately release tension/pressure, then release the key(s) rather gently — so minimal to no bounce) — when playing faster there's simply not enough time to be as gentle with key release. A lot of it comes down to key release speed (which luckily many keyboards measure), but for the extreme bounce we see, you really need very fast key release plus a very strong note (fortissimo + staccatissimo) to actually force the key to bounce up and then rebound.

Of course it doesn't affect the sound (much...I suppose the subtle sound could actually be modelled...), so probably pretty low priority! The "soft pedal" shifting the keys the wrong direction actually bothers me a little more, but again, low priority.

I was going to say the bounce is just too easy to trigger vs. on a physical piano, but then I checked the note-off velocities my VPC1 gives, and they tend to be way too high (so a Kawai issue). That can of course be fixed by adjusting the note-off curve in Pianoteq. I had already adjusted the lower velocities because the VPC1 doesn't seem to like registering many values between 1 and 24...which means I inadvertently made it *more* likely to register higher velocities.

So at this point I'll assume the key bounce is already well tuned, and it's just a VPC1 problem (and likely many other keyboards). Again, not that it's a big deal!

I do like how the lower (longer/heavier) keys bounce more than the high ones, which is very realistic.